你可以使用以下方法:

newStr = str.replace(/[^a-z0-9]/gi, '_');

or

newStr = str.replace(/[^a-zA-Z0-9]/g, '_');

这将替换所有不是字母或数字的字符('_')。简单地更改下划线值的任何你想替换它。

像这样使用正则表达式对象

var regex = new RegExp(' ' '， 'g'); STR = STR .replace(regex， '\ ");

它将取代所有出现的“into”。

我只是编写了一个基准测试，并测试了前3个答案。 对于短字符串(<500字符) 投票第三多的答案比投票第二多的答案快。

对于长字符串(在测试字符串中添加".repeat(300)")，回答1的速度越快，后面跟着第二个和第三个答案。

注意:

上述情况适用于使用v8引擎(chrome/chromium等)的浏览器。 使用firefox (SpiderMonkey引擎)，结果完全不同 你们自己看看吧!! Firefox的第三个解决方案似乎是 第一个解决方案比Chrome快4.5倍…疯狂:D

function log(data) { document.getElementById("log").textContent += data + "\n"; } benchmark = (() => { time_function = function(ms, f, num) { var z; var t = new Date().getTime(); for (z = 0; ((new Date().getTime() - t) < ms); z++) f(num); return (z / ms) } // returns how many times the function was run in "ms" milliseconds. function benchmark() { function compare(a, b) { if (a[1] > b[1]) { return -1; } if (a[1] < b[1]) { return 1; } return 0; } // functions function replace1(s) { s.replace(/foo/g, "bar") } String.prototype.replaceAll2 = function(_f, _r){ var o = this.toString(); var r = ''; var s = o; var b = 0; var e = -1; // if(_c){ _f = _f.toLowerCase(); s = o.toLowerCase(); } while((e=s.indexOf(_f)) > -1) { r += o.substring(b, b+e) + _r; s = s.substring(e+_f.length, s.length); b += e+_f.length; } // Add Leftover if(s.length>0){ r+=o.substring(o.length-s.length, o.length); } // Return New String return r; }; String.prototype.replaceAll = function(str1, str2, ignore) { return this.replace(new RegExp(str1.replace(/([\/\,\!\\\^\$\{\}\[\]\(\)\.\*\+\?\|\<\>\-\&])/g, "\\$&"), (ignore ? "gi" : "g")), (typeof(str2) == "string") ? str2.replace(/\$/g, "$$$$") : str2); } function replace2(s) { s.replaceAll("foo", "bar") } function replace3(s) { s.split('foo').join('bar'); } function replace4(s) { s.replaceAll2("foo", "bar") } funcs = [ [replace1, 0], [replace2, 0], [replace3, 0], [replace4, 0] ]; funcs.forEach((ff) => { console.log("Benchmarking: " + ff[0].name); ff[1] = time_function(2500, ff[0], "foOfoobarBaR barbarfoobarf00".repeat(10)); console.log("Score: " + ff[1]); }) return funcs.sort(compare); } return benchmark; })() log("Starting benchmark...\n"); res = benchmark(); console.log("Winner: " + res[0][0].name + " !!!"); count = 1; res.forEach((r) => { log((count++) + ". " + r[0].name + " score: " + Math.floor(10000 * r[1] / res[0][1]) / 100 + ((count == 2) ? "% *winner*" : "% speed of winner.") + " (" + Math.round(r[1] * 100) / 100 + ")"); }); log("\nWinner code:\n"); log(res[0][0].toString()); <textarea rows="50" cols="80" style="font-size: 16; resize:none; border: none;" id="log"></textarea>

当您单击按钮时，测试将运行10s (+2s)。

我的结果(在同一台电脑上):

Chrome/Linux Ubuntu 64:
1. replace1 score: 100% *winner* (766.18)
2. replace4 score: 99.07% speed of winner. (759.11)
3. replace3 score: 68.36% speed of winner. (523.83)
4. replace2 score: 59.35% speed of winner. (454.78)

Firefox/Linux Ubuntu 64
1. replace3 score: 100% *winner* (3480.1)
2. replace1 score: 13.06% speed of winner. (454.83)
3. replace4 score: 9.4% speed of winner. (327.42)
4. replace2 score: 4.81% speed of winner. (167.46)

很乱，是吧?

擅自增加了更多的测试结果

Chrome/Windows 10
1. replace1 score: 100% *winner* (742.49)
2. replace4 score: 85.58% speed of winner. (635.44)
3. replace2 score: 54.42% speed of winner. (404.08)
4. replace3 score: 50.06% speed of winner. (371.73)

Firefox/Windows 10
1. replace3 score: 100% *winner* (2645.18)
2. replace1 score: 30.77% speed of winner. (814.18)
3. replace4 score: 22.3% speed of winner. (589.97)
4. replace2 score: 12.51% speed of winner. (331.13)

Edge/Windows 10
1. replace1 score: 100% *winner* (1251.24)
2. replace2 score: 46.63% speed of winner. (583.47)
3. replace3 score: 44.42% speed of winner. (555.92)
4. replace4 score: 20% speed of winner. (250.28)

Galaxy Note 4上的Chrome

1. replace4 score: 100% *winner* (99.82)
2. replace1 score: 91.04% speed of winner. (90.88)
3. replace3 score: 70.27% speed of winner. (70.15)
4. replace2 score: 38.25% speed of winner. (38.18)

我不知道最快的是什么，但我知道最易读的是什么——最短最简单的是什么。即使它比其他溶液慢一点，也值得使用。

所以使用:

 "string".replace("a", "b");
 "string".replace(/abc?/g, "def");

享受好的代码而不是更快的速度(嗯…1/100000秒不是差)和丑陋的差。；）

var mystring = 'This is a string';
var newString = mystring.replace(/i/g, "a");

newString现在是'Thas as a strange '

你可以使用以下方法:

newStr = str.replace(/[^a-z0-9]/gi, '_');

or

newStr = str.replace(/[^a-zA-Z0-9]/g, '_');

这将替换所有不是字母或数字的字符('_')。简单地更改下划线值的任何你想替换它。